```html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>数据库事务隔离级别详解</title>
    <link rel="stylesheet" href="https://cdn.staticfile.org/font-awesome/6.4.0/css/all.min.css">
    <link rel="stylesheet" href="https://cdn.staticfile.org/tailwindcss/2.2.19/tailwind.min.css">
    <link href="https://fonts.googleapis.com/css2?family=Noto+Serif+SC:wght@400;500;600;700&family=Noto+Sans+SC:wght@300;400;500;700&display=swap" rel="stylesheet">
    <style>
        body {
            font-family: 'Noto Sans SC', Tahoma, Arial, Roboto, "Droid Sans", "Helvetica Neue", "Droid Sans Fallback", "Heiti SC", "Hiragino Sans GB", Simsun, sans-serif;
            color: #333;
            line-height: 1.6;
        }
        .serif {
            font-family: 'Noto Serif SC', serif;
        }
        .hero-gradient {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
        }
        .card-hover:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1);
        }
        .isolation-level-card {
            transition: all 0.3s ease;
        }
        .isolation-level-card:hover {
            transform: translateY(-3px);
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
        }
        .divider {
            height: 3px;
            background: linear-gradient(90deg, rgba(102,126,234,0.5) 0%, rgba(118,75,162,0.5) 100%);
        }
        .problem-card {
            transition: all 0.3s ease;
            border-left: 4px solid transparent;
        }
        .problem-card:hover {
            transform: translateY(-3px);
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
        }
        .dirty-read {
            border-left-color: #ef4444;
        }
        .non-repeatable-read {
            border-left-color: #f59e0b;
        }
        .phantom-read {
            border-left-color: #10b981;
        }
        .animate-float {
            animation: float 6s ease-in-out infinite;
        }
        @keyframes float {
            0% { transform: translateY(0px); }
            50% { transform: translateY(-10px); }
            100% { transform: translateY(0px); }
        }
    </style>
</head>
<body class="bg-gray-50">
    <!-- Hero Section -->
    <section class="hero-gradient text-white py-20 px-4 md:px-0">
        <div class="container mx-auto max-w-6xl flex flex-col md:flex-row items-center">
            <div class="md:w-1/2 mb-10 md:mb-0">
                <h1 class="serif text-4xl md:text-5xl font-bold mb-6 leading-tight">数据库事务隔离级别</h1>
                <p class="text-xl mb-8 opacity-90">探索并发控制的核心概念与最佳实践</p>
                <p class="opacity-90 mb-8">事务隔离级别是数据库管理系统用来控制并发访问的重要机制，它定义了事务之间的可见性和相互影响的程度，直接影响系统的并发性能和数据一致性。</p>
                <div class="flex space-x-4">
                    <a href="#levels" class="bg-white text-indigo-700 px-6 py-3 rounded-md font-medium hover:bg-opacity-90 transition duration-300">隔离级别</a>
                    <a href="#problems" class="bg-indigo-800 text-white px-6 py-3 rounded-md font-medium hover:bg-opacity-90 transition duration-300">并发问题</a>
                </div>
            </div>
            <div class="md:w-1/2 flex justify-center">
                <div class="relative w-64 h-64 md:w-80 md:h-80">
                    <div class="absolute inset-0 bg-white bg-opacity-20 rounded-full animate-float"></div>
                    <div class="absolute inset-4 bg-white bg-opacity-20 rounded-full animate-float" style="animation-delay: 0.5s;"></div>
                    <div class="absolute inset-8 bg-white bg-opacity-20 rounded-full animate-float" style="animation-delay: 1s;"></div>
                    <div class="absolute inset-12 bg-white bg-opacity-20 rounded-full animate-float" style="animation-delay: 1.5s;"></div>
                </div>
            </div>
        </div>
    </section>

    <!-- Introduction Section -->
    <section class="py-16 px-4 md:px-0">
        <div class="container mx-auto max-w-4xl">
            <div class="bg-white rounded-xl shadow-md overflow-hidden p-8 card-hover transition duration-500">
                <p class="text-lg leading-relaxed">
                    事务隔离级别是数据库管理系统（DBMS）用来控制并发访问的一个重要概念。隔离级别定义了事务之间的可见性和相互影响的程度。在SQL标准中，定义了四个事务隔离级别，分别是读未提交（Read Uncommitted）、读已提交（Read Committed）、可重复读（Repeatable Read）和串行化（Serializable）。不同的隔离级别权衡了事务的并发性和一致性，选择合适的隔离级别取决于具体应用的需求。
                </p>
            </div>
        </div>
    </section>

    <!-- Isolation Levels Section -->
    <section id="levels" class="py-16 px-4 md:px-0 bg-gray-50">
        <div class="container mx-auto max-w-6xl">
            <h2 class="serif text-3xl font-bold text-center mb-4">四种事务隔离级别</h2>
            <p class="text-center text-gray-600 mb-12 max-w-2xl mx-auto">SQL标准定义了四种隔离级别，MySQL全都支持。从上往下，隔离强度逐渐增强，性能逐渐变差。</p>
            
            <div class="grid md:grid-cols-2 lg:grid-cols-4 gap-6">
                <!-- Read Uncommitted -->
                <div class="isolation-level-card bg-white rounded-lg shadow-sm p-6 border-t-4 border-red-400">
                    <div class="flex items-center mb-4">
                        <div class="w-10 h-10 rounded-full bg-red-100 flex items-center justify-center mr-4">
                            <i class="fas fa-eye-slash text-red-500"></i>
                        </div>
                        <h3 class="serif text-xl font-bold">读未提交</h3>
                    </div>
                    <p class="text-gray-600 mb-4">READ UNCOMMITTED</p>
                    <p class="text-gray-700">最低隔离级别，允许读取未提交的数据变更，可能导致脏读、不可重复读和幻读。</p>
                </div>
                
                <!-- Read Committed -->
                <div class="isolation-level-card bg-white rounded-lg shadow-sm p-6 border-t-4 border-yellow-400">
                    <div class="flex items-center mb-4">
                        <div class="w-10 h-10 rounded-full bg-yellow-100 flex items-center justify-center mr-4">
                            <i class="fas fa-eye text-yellow-500"></i>
                        </div>
                        <h3 class="serif text-xl font-bold">读已提交</h3>
                    </div>
                    <p class="text-gray-600 mb-4">READ COMMITTED</p>
                    <p class="text-gray-700">只读取已提交的数据，防止脏读，但仍可能出现不可重复读和幻读。</p>
                </div>
                
                <!-- Repeatable Read -->
                <div class="isolation-level-card bg-white rounded-lg shadow-sm p-6 border-t-4 border-green-400">
                    <div class="flex items-center mb-4">
                        <div class="w-10 h-10 rounded-full bg-green-100 flex items-center justify-center mr-4">
                            <i class="fas fa-redo text-green-500"></i>
                        </div>
                        <h3 class="serif text-xl font-bold">可重复读</h3>
                    </div>
                    <p class="text-gray-600 mb-4">REPEATABLE READ</p>
                    <p class="text-gray-700">MySQL默认级别，确保事务中多次读取同样数据结果一致，防止脏读和不可重复读，但可能仍有幻读。</p>
                </div>
                
                <!-- Serializable -->
                <div class="isolation-level-card bg-white rounded-lg shadow-sm p-6 border-t-4 border-purple-400">
                    <div class="flex items-center mb-4">
                        <div class="w-10 h-10 rounded-full bg-purple-100 flex items-center justify-center mr-4">
                            <i class="fas fa-lock text-purple-500"></i>
                        </div>
                        <h3 class="serif text-xl font-bold">串行化</h3>
                    </div>
                    <p class="text-gray-600 mb-4">SERIALIZABLE</p>
                    <p class="text-gray-700">最高隔离级别，完全串行执行事务，防止所有并发问题，但性能最差。</p>
                </div>
            </div>
        </div>
    </section>

    <!-- Comparison Chart Section -->
    <section class="py-16 px-4 md:px-0">
        <div class="container mx-auto max-w-6xl">
            <h2 class="serif text-3xl font-bold text-center mb-12">隔离级别对比</h2>
            <div class="bg-white rounded-xl shadow-md overflow-hidden">
                <div class="overflow-x-auto">
                    <table class="min-w-full divide-y divide-gray-200">
                        <thead class="bg-gray-50">
                            <tr>
                                <th scope="col" class="px-6 py-3 text-left text-xs font-medium text-gray-500 uppercase tracking-wider">隔离级别</th>
                                <th scope="col" class="px-6 py-3 text-left text-xs font-medium text-gray-500 uppercase tracking-wider">脏读</th>
                                <th scope="col" class="px-6 py-3 text-left text-xs font-medium text-gray-500 uppercase tracking-wider">不可重复读</th>
                                <th scope="col" class="px-6 py-3 text-left text-xs font-medium text-gray-500 uppercase tracking-wider">幻读</th>
                                <th scope="col" class="px-6 py-3 text-left text-xs font-medium text-gray-500 uppercase tracking-wider">性能</th>
                            </tr>
                        </thead>
                        <tbody class="bg-white divide-y divide-gray-200">
                            <tr>
                                <td class="px-6 py-4 whitespace-nowrap text-sm font-medium text-gray-900">读未提交</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-times text-red-500"></i> 可能</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-times text-red-500"></i> 可能</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-times text-red-500"></i> 可能</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-bolt text-green-500"></i> 最高</td>
                            </tr>
                            <tr>
                                <td class="px-6 py-4 whitespace-nowrap text-sm font-medium text-gray-900">读已提交</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-check text-green-500"></i> 防止</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-times text-red-500"></i> 可能</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-times text-red-500"></i> 可能</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-bolt text-green-500"></i> 高</td>
                            </tr>
                            <tr>
                                <td class="px-6 py-4 whitespace-nowrap text-sm font-medium text-gray-900">可重复读</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-check text-green-500"></i> 防止</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-check text-green-500"></i> 防止</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-times text-red-500"></i> 可能</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-bolt text-yellow-500"></i> 中</td>
                            </tr>
                            <tr>
                                <td class="px-6 py-4 whitespace-nowrap text-sm font-medium text-gray-900">串行化</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-check text-green-500"></i> 防止</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-check text-green-500"></i> 防止</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-check text-green-500"></i> 防止</td>
                                <td class="px-6 py-4 whitespace-nowrap text-sm text-gray-500"><i class="fas fa-bolt text-red-500"></i> 低</td>
                            </tr>
                        </tbody>
                    </table>
                </div>
            </div>
        </div>
    </section>

    <!-- Usage Suggestions Section -->
    <section class="py-16 px-4 md:px-0 bg-gray-50">
        <div class="container mx-auto max-w-4xl">
            <div class="bg-indigo-50 rounded-xl p-8 border border-indigo-100">
                <div class="flex items-start">
                    <div class="flex-shrink-0 h-10 w-10 rounded-full bg-indigo-100 flex items-center justify-center mr-4">
                        <i class="fas fa-lightbulb text-indigo-500"></i>
                    </div>
                    <div>
                        <h3 class="serif text-xl font-bold mb-4">使用建议</h3>
                        <ul class="space-y-3 text-gray-700">
                            <li class="flex items-start">
                                <i class="fas fa-check-circle text-indigo-500 mt-1 mr-2"></i>
                                <span>选择隔离级别时，需要根据具体业务需求权衡一致性和并发性的要求。</span>
                            </li>
                            <li class="flex items-start">
                                <i class="fas fa-check-circle text-indigo-500 mt-1 mr-2"></i>
                                <span>低隔离级别可能带来更高的并发性，但也增加了一致性问题的可能性。</span>
                            </li>
                            <li class="flex items-start">
                                <i class="fas fa-check-circle text-indigo-500 mt-